OBJECTIVE: The designing and building of a system capable of automatically determining the amino acid sequences of proteins. As finally developed the system is intended to be self-contained, the decisions being made on line, with operator intervention being gradually reduced and relegated to higher and higher level decisions as the automatic laboratory acquires its full capacity. APPROACH: A modular approach is being observed, with chemical process flow and information flow systems intended to provide the extensive flexibility required to prosecute efficiently the required manifold variations of procedure. This flexibility will in large part be imparted by a central storage and dispensing module from which measured samples can be directed to any one of the peripheral modules for appropriate processing. Such a design also renders the overall laboratory capable of indefinite expansion as new protein sequencing procedures are developed either to replace or add to older procedures represented by modules of actual operation. The peripheral modules presently projected are: (1) Protein and peptide fragmentation module; (2) Peptide separation modules; (3) Automatic hydrolysis module; (4) Amino acid module; (5) Sequence determination module. The computer organization will consist of a network in which several instrument dedicated mini-computers are connected to a central computer and an operators console, each peripheral computer being capable of undertaking the tasks of any other, using a file of programs rather than one overall program.